Hi Greg, when ca is low, you have to stop dosing alk in order to get the ca to rise. Just adding more ca won't make it change.

Hmm, I never noticed it stop me from raising Ca. Of course I can't test it out now as my tank is in pieces :neutral:

Where did you get that misinformation from and which brand of salt are you using? I'm assuming its Instant Ocean. If that is the case you're starting out with saltwater that has high Alkalinity and low(ish) Calcium. So yes you're going to have to dose or add a disproportionately larger amount of Calcium supplement to get it up to an optimal level... and every time you perform a water change you're going to push your Alkalinity up and dilute Calcium down. Many people get around this issue by simply adding a little Calcium supplement (like Calcium Chloride) to their water change water. Alternatively you could choose to use a brand with really high Calcium... or even a well balanced brand if such a thing exists. In any case, test your newly mixed water change water to find out what the levels are that you're starting from.

I thought about it and I believe I understand what you were thinking. You are correct in that you can't use a product like Kalkwasser or an all in one calcium carbonate supplement to increase Calcium without also Increasing Alkalinity. But you absolutely can continue to maintain Alkalinity by dosing your maintenance amount while also dosing a larger amount of Calcium to raise it at the same time.